Pull Your Leg

The genuine origin of this one has simply never been found, despite the phrase feeling old and folksy. The earliest reliable printed record is from 1883, and no version from before roughly 1821 has ever turned up. Two competing theories get repeated constantly: that London thieves would literally pull at a victim's leg to trip them before robbing them once they were down, or that it relates somehow to public hangings at Tyburn, where an executioner or bystander pulling on a hanged person's legs supposedly hastened their death. Both stories are colourful. Neither has any real supporting evidence, the details shift depending on who's telling it, and no historian has managed to connect either practice convincingly to this specific, much gentler phrase about teasing.